Infections by members of the Chlamydiaceae family constitute a growing public health problem. Two key pathogens for man are (1) Chlamydia trachomatis, agent of trachoma and sexually transmitted disease and (2) Chlamydia pneumoniae, agent of community acquired pneumonia and a leading pathogen candidate for initiation or exacerbation of chronic diseases. Such chronic diseases include, for example, atherosclerosis, cardiac artery disease, chronic obstructive pulmonary disease and neural pathologies such as multiple sclerosis and Alzheimer's disease.
The lack of methods to detect infectious as well as persistent chlamydia in patients is a public health problem. Simple identification and quantification methods are needed because these bacteria are “stealth” pathogens, frequently present, but not obviously in evidence. In addition, chlamydia cells were generally thought to occur infrequently if at all in blood, a routinely sampled biological fluid. As a result, tests to detect these pathogens are often not performed. Further, certain tests are invasive, often requiring biopsy followed by demonstration of the pathogen in tissue samples.